Project Summary Retinal disorders are a common cause of debilitating vision loss. For many of these conditions, including retinal detachments and macular holes, the only treatment is surgery. The first step of all such surgeries is vitrectomy, the process of removing the vitreous gel through tiny ports in the front of the eye. Each year, 1.1 million vitrectomies are performed globally with 300,000 performed in the US alone, and in the majority of these cases a retinal tamponade is required to be left in the eye to maintain pressure on the retina and aid healing. The global retinal tamponade market was recently valued at USD $64.5 million in 2013 and is predicted to reach USD $77.5 million by 2020. The current state of the art uses either an expansile gas, or a silicone oil to exert pressure on the retina during healing (tamponade). However, neither method is ideal and therefore to address these deficiencies, this phase 2 proposal extends early work we performed on a novel hydrogel that uses two common synthetic biomedical polymers, namely a modified poly(vinyl alcohol) and poly(ethylene glycol) in a form that creates a unique hydrogel system that is very low viscosity in liquid form but then gels through crosslink formation in the eye. This formulation allows for injection through small surgical ports followed by in vivo expansion resulting in 360-degree retinal tamponade. This unique formulation will eliminate the need for post-operative patient positioning and will degrade to small molecules that are readily cleared from the eye over the period of 3-5 weeks providing a temporary tamponade force before degrading. Data from the Phase 1 supports that the resulting device will be more patient friendly with almost no refractive issues and the ability for the patient to be fully mobile and has proven degradation over 2-3 weeks with no inflammatory response, although this degradation time is also tunable. In this Phase 2 we intend to refine the formulation for improved performance and validate it within a relevant model to demonstrate efficacy.